Merge "C2SoftMpeg4Enc: Do not return 0 byte CSD for H263" am: 386643fc4d am: ca5dfc3cc3 am: 4f587a02ca am: 31ec0f5cd3

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/1773666

Change-Id: I9b24fb5abaa3f370774cca036b93175a36030941